Abstract
Highly mixed and bonded Ti-Al powders were made by mechanical alloying (MA) method, and these powders were plasma sprayed on the mild steel substrate under the reduced pressure conditions. Moreover, to fabricate the intermetallic matrix composite coatings, Ti-Al/Si3N4 MA pre-composite powders were made and plasma sprayed. Mo-Si system was also applied to make the intermetallic coating. The results obtained are summarized as follows;
(1) The moderate MA powders, which have moderate powder size and highly mixed structure between two metal materials, could be prepared by selecting the moderate MA conditions.
(2) Ti3Al intermetallic coatings were made by just plasma spraying of MA powders without after heat treatment. Intermetallic matrix composite coatings were also made by the similar spray process. The Ti3Al matrix composite coating had a Vickers hardness of about 1000.
(3) The phase obtained by spraying of Mo-Si MA powder was fairly complicated. More detailed observation was required in this system.
